Ever wonder why the ocean is blue?

It's caused from a scattering of sunlight by tiny particles (phytoplankton) suspended in the water. Blue light, being of short wavelength, is dispersed more effectively than light of longer wavelengths.

Although waters of the open ocean are commonly some shade of blue, especially in tropical or subtropical regions, green water is commonly observed near coastlines. Green colored shoreline water is caused by yellow pigments being mixed with blue water.

Other microscopic plants may color the water brown or brownish-red. Near shore silt or sediment in suspension can give waters a brownish hue, while outflow of large rivers can often be observed for miles offshore by the coloration of suspended soil particles.

Colors of the sea change constantly because of clouds passing across the face of the sun or because of the angle of the sun's rays passing through the atmosphere.

Ever wonder what causes waves?

Commonly seen waves on the surface are caused principally by wind. However, submarine earthquakes, volcanic eruptions, and tides also cause waves. A breeze of less than two knots (two nautical miles per hour) can form surface ripples. As wind speeds increase, larger waves form. A wave height in feet usually will exceed half the wind speed, although individual waves could be greater.

So long as the wind blows consistently from the same direction, waves are referred to as sea. When the wind stops or changes direction, waves that continue in a direction different from that of the local winds are called swells.

Sometimes these waves can get mighty high.

Probably the highest wave measured with any degree of accuracy was reported by a ship traveling from Manila to San Diego in 1933. The waves in question were 112 feet high and were produced by winds of 60-68 knots operating over a fetch of several thousand miles.

Most waves we'll see are less than 12 feet. Waves more than 25 feet high are rare, and waves in excess of 50 feet develop only during very severe storms.

Tidal waves are caused by movement on the ocean floor and are commonly called seismic sea waves.

Submarine earthquakes, landslides, or volcanic eruptions create seismic sea waves. A submarine disturbance may produce three or four waves with a wave length (crest to crest) greater than three miles, although their height over the open ocean may be only one foot.

Speed of advance can exceed 500 miles per hour. As the waves approach shore, they are slowed and the water behind piles up to tremendously destructive heights.

Scientists can now predict tidal waves through seismograph stations hours before a tidal wave hits land.

Kinetic energy contained in waves is tremendous. A four-foot, 10-second wave striking a coast expends more than 35,000 horsepower per mile of coast. Examples are seen in coastlines hit by hurricanes.

And, if kinetic energy in waves is awesome, think about the pressure of water at 3,000-foot depths. Scientists say that 1,350 pounds of pressure per square inch occurs at that depth which is sufficient pressure to squeeze a block of wood to half its volume.